Researchers in the 1990s identified hydroxy derivatives of some fatty acids in macroalgae (seaweeds) and described the possible role of these compounds in wound healing and cell signaling in the organisms (Gerwick & Bernart 1993; Gerwick et al 1993; Gerwick 1994). They recognized these compounds to be similar to those produced in the human body through the lipoxygenase pathway. These same researchers also attempted to develop cell suspension cultures of these seaweeds to produce eicosanoids and related oxylipins from the C18 fatty acids, linoleic acid, and linolenic acid, and from arachidonic acid (C20:4n-6) (ARA) in the red, brown and green seaweeds. However, production of seaweed biomass in these cultures systems proved to be very poor (e.g. about 0.6 to 1.0 g/L seaweed biomass after 15 days (Rorrer et al. 1996)) and even direct addition of key fatty acids to the cultures only minimally increased production of oxylipins over that of controls (Rorrer et al. 1997). Additionally, in some cases, the added free fatty acids proved toxic to the cultures (Rorrer et al. 1997). Therefore these systems have only remained academically interesting for producing oxygenated forms of these fatty acids, and studies continue on these C18 and C20 oxylipins in these seaweeds (e.g., Bouarab et al. 2004).
The oxylipins from the long chain omega-6 (n-6 or ω-6 or N6) fatty acid, ARA, have been well studied and are generally considered to be proinflammatory in humans. Oxylipins from the long chain omega-3 (n-3 or ω-3 or N3) fatty acids, however, have generally been found to be anti-inflammatory. In the early 2000's, Serhan and other researchers discovered that hydroxylated forms of two long chain omega-3 polyunsaturated fatty acids (omega-3 LCPUFAs) (i.e., eicosapentaenoic acid (C20:5, n-3) (EPA) and docosahexaenoic acid C22:6, n-3) (DHA)) were made in the human body (Serhan et al. 2004a,b; Bannenberg et al. 2005a,b) They identified pathways whereby the omega-3 LCPUFAs, EPA and DHA, were processed by cyclooxygenases, acetylated cyclooxygenase-2 or by lipoxygenase enzymes, resulting in production of novel mono-, di- and tri-hydroxy derivatives of these fatty acids. The resulting compounds, which were named “resolvins” (because they were involved in the resolution phase of acute inflammation) or docosatrienes (because they were made from docosahexaenoic acid and contain conjugated double bonds), were determined to have strong anti-inflammatory (Arita et al. 2005a,b,c; Flower & Perretti 2005; Hong et al. 2003; Marcjeselli et al. 2003; Ariel et al. 2005), antiproliferative, and neuroprotective (Bazan 2005a,b; Bazan et al. 2005; Belayev et al. 2005; Butovich et al. 2005; Chen & Bazan 2005; Lukiw et al. 2005; Mukherjee et al 2004) properties. These compounds were also noted to have longer half-lives in the human body as compared to other types of eicosanoids.
In the past few years, various patents and patent application publications have described analogs of hydroxy derivatives of ARA, DHA and EPA, the pathways by which they are formed, methods for their synthesis in the laboratory via organic synthetic means or through biogenesis using cyclooxygenase or lipoxygenase enzymes, and use of these hydroxy derivatives as pharmaceutical compounds for the treatment of inflammatory diseases. These patents and publications are summarized briefly below.
U.S. Pat. No. 4,560,514 describes the production of both pro-inflammatory (LX-A) and anti-inflammatory tri-hydroxy lipoxins (LX-B) derived from arachidonic acid (ARA). Use of these compounds in both studying and preventing inflammation (as pharmaceutical compounds) are also described.
U.S. Patent Application Publication No. 2003/0166716 describes the use of lipoxins (derived from ARA) and aspirin-triggered lipoxins in the treatment of asthma and inflammatory airway diseases. Chemical structures of various anti-inflammatory lipoxin analogs are also taught.
U.S. Patent Application Publication No. 2003/0236423 discloses synthetic methods based on organic chemistry for preparing trihydroxy polyunsaturated eicosanoids and their structural analogs including methods for preparing derivatives of these compounds. Uses for these compounds and their derivatives in the treatment of inflammatory conditions or undesired cell proliferation are also discussed.
PCT Publication No. WO 2004/078143 is directed to methods for identifying receptors that interact with di- and tri-hydroxy EPA resolving analogs.
U.S. Patent Application Publication No. 2004/0116408A1 discloses that the interaction of EPA or DHA in the human body with cyclooxygenase-11 (COX2) and an analgesic such as aspirin leads to the formation of di- and tri-hydroxy EPA or DHA compounds with beneficial effects relating to inflammation. It also teaches methods of use and methods of preparing these compounds.
U.S. Patent Application Publication No. 2005/0075398A1 discloses that the docosatriene 10,17S-docosatriene (neuroprotectin D1) appears to have neuroprotective effects in the human body.
PCT Publication No. WO 2005/089744A2 teaches that di- and tri-hydroxy resolvin derivatives of EPA and DHA and stable analogs thereof are beneficial in the treatment of airway diseases and asthma.
U.S. Patent Publication No. 2006/0293288 describes the use of EPA and DHA resolvis for treatment of gastrointestinal diseases.
While the references above describe lipoxins derived from ARA and docosatrienes and resolvins derived from DHA and EPA, as well as various applications of such compounds, there remains a need in the art for alternative ways of delivering the anti-inflammatory benefits and other benefits of these LCPUFA oxylipins (and in particular docosanoids) to consumers other than by providing consumers with combinations of LCPUFA oil and aspirin or by chemically synthesizing these derivatives or their analogs.
Moreover, none of the references above describe methods for making these specific compounds in microbial cultures or plants, nor do they describe methods for increasing the content of these beneficial hydroxy fatty acid derivatives in edible oils. In addition, none of these references describe any hydroxy derivatives from other LCPUFAs, nor do any of these references suggest that that there could be a beneficial role for hydroxy derivatives of any LCPUFAs other than ARA, DHA and EPA.